HRV tracking last 4 years

Hello, I am interested in understanding HRV better. I am using emfitQS and have looked at my HRV going back to JAN 2019. It seems that overall reduced physical activity has negatively impacted my HRV.
L-arm injury which started -3/4 months before Covid-10 lockdowns, then the Fires which reduced going outside, Working from home due to lock downs and reduced/eliminated rowing/lifting/pull-ups due to L-Arm injury.

I recently discovered that there might be a direct connection between how hot I am during sleep to how well I recover.
e.g. I stopped using a thick duck down blanket which immediately spiked my HRV/RMSSD
If I covered my legs with that blanket after a few days it did not negatively effect HRV, but if if covered my upper body it did. I got a new top blanket with holes in it ( Bearaby hug? (Weighted blanket )

Also a week ago I replaced my Garmin Fenix 5 with the apple 7 watch. The HR and other metrics seem to be much more refined. The HR is right on with a Polar H10 during biking on Peloton( which I got 2 months ago and regret not getting 2 years ago ).
The cardio from biking was not raising my HRV / recovery which made me worried which lead to the being hot and sweaty theory of impacting sleep recovery.

TDLR:
Less exercise & movement = worse HRV?
Being hot while sleeping = bad sleep recovery?

Hi Mano, my go to source on HRV is Marco Altini.

A treasure trove at the link above.